The present invention relates generally to the trailer towing field and, more particularly, to a new and improved weight distributing hitch assembly which also provides trailer sway control.
Hitch assemblies for more evenly distributing the tow weight of a trailer over the front and rear wheels of a towing vehicle are well known in the art. Examples of weight distributing hitch assemblies of the type being described may be found in U.S. Pat. Nos. 5,375,867 and 5,465,991 to Kass et al. owned by Reese Products, Inc., the assignee of the present invention. Such hitch assemblies include a hitch bar for mounting in a trailer hitch receiver secured to the towing vehicle and a ball mount head for mounting on the hitch bar at a selected tilt angle. A pair of lift units are secured to the opposing rails of the trailer frame. A pair of spring bars are mounted at their proximal ends to the ball mount head and held by the lift units at their distal ends. In operation, the lift units allow one to adjust the amount of leveling or load transfer provided by the spring bars.
More recently, weight distributing hitch assemblies with integral trailer sway control have been developed. The weight distributing hitch assembly utilized with this prior art sway control system includes a ball mount head and a pair of spring bars. Each spring bar carries a cam follower at its projecting, distal end. The dual cam sway control system consists of a pair of one-piece cam arms, each cam arm having a proximal end pivotally mounted to a bracket secured to one of the frame rails of the trailer and a distal end carrying a cam for receiving the cam follower of a spring bar. Each bracket is secured to a frame rail of the trailer by a pair of U-bolts. These U-bolts allow the selective positioning of the brackets. As a consequence, the position of the cams at the ends of the cam arms may be selectively adjusted to insure proper meeting of the cams with the cam followers of the spring bars so as to provide the desired anti-sway and weight distributing performance.
While such a U-bolt adjustment system generally functions admirably for its intended purpose, in certain applications it has been found that gas bottles, trailer jacks and/or other trailer equipment or accessories may interfere with the U-bolt mounting system. Accordingly, a need exists for an alternative to this approach.
To achieve the foregoing and other objects, and in accordance with the purposes of the present invention as described herein, an improved weight distributing hitch assembly is provided for towing a trailer behind a vehicle. The weight distributing hitch assembly includes a ball mount head which may be mounted to and carried upon a hitch bar secured in the receiver box of a trailer hitch receiver mounted to a towing vehicle. The weight distributing hitch assembly also includes a pair of spring bars. Each of the pair of spring bars includes a first end secured to the ball mount head and a second projecting end. The weight distributing hitch assembly also includes a pair of adjustable length cam arms. Each of the pair of cam arms has a proximal end mounted to the trailer and a distal end for engaging and supporting the second, projecting end of one of the pair of spring bars. Further, the weight distributing hitch assembly also includes a pair of lift units carried on the trailer and a pair of lift chains. A lift chain extends between each one of the distal ends of the pair of adjustable length cam arms and its corresponding lift unit.
Additionally, the second projecting end of each of the pair of spring bars includes a cam follower and the distal end of each of the pair of adjustable length cam arms includes a cam. The cooperating cam followers and cams function in a manner that provides resistance to trailer sway and thus, trailer sway control of the trailer being towed behind the towing vehicle,
In accordance with yet another aspect of the present invention, the first end of each of the pair of spring bars may include a trunnion head that is received to allow relative pivotal movement in the ball mount head. Such a trunnion head is disclosed, for example, in U.S. Pat. No. 5,562,298 to Kass et al., the full disclosure of which is incorporated by reference.
More specifically describing the invention, the weight distributing hitch assembly for towing a trailer behind the towing vehicle includes a ball mount head and a pair of spring bars. Each of the pair of spring bars includes a first end secured to the ball mount head and a second projecting end. The weight distributing hitch assembly also includes a pair of adjustable length cam arms. Each of the pair of adjustable length cam arms includes (a) a first segment having a cam at a first terminus thereof and an elongated slot adjacent a second terminus thereof and (b) a second segment having a head at a proximal end thereof for securing to a mounting bracket by means of a pivot pin and a fastener carried adjacent a distal end thereof for engaging in the elongated slot of the first segment.
Still further, the weight distributing hitch assembly includes a pair of lift units carried on the trailer and a pair of lift chains. One of the lift chains extends between the first terminus of one of the adjustable length cam arms and one of the pair of lift units. The other of the lift chains extends between the first terminus of the other of the adjustable length cam arms and the other of the pair of lift units.
Preferably, the second end of each of the spring bars includes a cam follower that engages the cam on the first terminus of the first segment of one of the pair of adjustable cam arms. Further, the first end of each of said pair of spring bars includes a trunnion head that is received to allow relative pivotal movement in the ball mount head. In addition, each of the pair of lift units includes a mounting bracket, a wishbone lever pivotally mounted to the mounting bracket and a lift chain receiving lug carried on the wishbone lever. Further, the first segment includes a securing loop adjacent the first terminus for engaging one of the pair of lift chains.
Still other objects of the present invention will become apparent to those skilled in this art from the following description wherein there is shown and described a preferred embodiment of this invention, simply by way of illustration of one of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.